The B-7 is a
7 wire braided geometry that uses a single 10 gauge ground cable
and three 16 gauge cables for hot and three 16 gauge cables for
neutral. So the total gauge of the two legs are 11 gauge each.
The 10 gauge
ground is multi-stranded and uses a 20 mil nylon coated insulator.
The 16 gauge
conductors used for hot and neutral are solid core high purity Copper
(99.98%) with a 30 mil polyethylene insulator.